Exercise appliance for abdominal muscles and method of using same

ABSTRACT

An exercise appliance for conditioning the abdominal muscles of an individual includes an elastically resilient structure presenting a yieldable contact surface which provides a restoring force against a force applied thereto. The contact surface has a contour suitably sized and shaped to be at least partially fittable in the space formed between a support surface and a static lordotic curve of a lumbar back of an individual positioned with a remaining portion of the back of the individual in contact with the support surface. By positioning the resiliently yieldable portion of the appliance in the space formed between a support surface and the lumbar back, subsequent attempts by the individual to straighten the lumbar curvature by contraction of the abdominal muscles, forces the lumbar spine to flatten against the counter-force provided by the appliance, conditioning the abdominal muscles responsible for the action. In a further embodiment, the exercise appliance allows selection of the degree of resistance provided by the contact surface, allowing efficient use by individuals of varying levels of physical conditioning.

REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation-in-part of co-pendingapplication Ser. No. 08/442,182 filed May 16, 1995 entitled EXERCISEAPPLIANCE FOR ABDOMINAL MUSCLES AND METHOD OF USING SAME.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to an exercise appliance and amethod of using the same for strengthening the abdominal muscles of auser.

[0003] Proper conditioning of the abdominal muscles, and primarily therectus abdominous, is important not only for purposes of cosmeticappearance, but for maintaining integrity of the lower back byinhibiting hyperextension of the lumbar vertebrae. Weakness of therectus abdominous results in an inability to flex the spine, making itparticularly difficult to raise the head and upper trunk from a supineposition. Uncorrected, this weakness can result in an increased lordoticcurve and may become a source of chronic pain.

[0004] An understanding of the anatomical structure of the human spine,as well as the actions of associated muscle groups, is important to thedevelopment of an exercise appliance effective in isolating involvementto the rectus abdominous, and which limits the deleterious effects onthe vertebrae caused heretofore.

[0005] The human spine, when viewed from the side, has three basicphysiologic curves along its mobile length, each curve associated with aparticular region thereof. Occupying the uppermost position along thespine is the cervical region, having a lordotic curvature, i.e. onehaving anterior convexity. Below the cervical spine is the thoracicregion having a curve which is convex posteriorly, referred to as thethoracic or dorsal kyphosis. The next, and lowest curve, is the lumbarregion. The lumbar curve is lordotic and of greater curvature than thethoracic curve. Each of the curved regions meets along a midline centerof gravity to balance against gravity and provide a stable, uprightposture.

[0006] The mobility of the three regions of the spine are determined byposterior vertebral articulations, the structure of which differs foreach region. Specifically, the articulating surfaces in the thoracicregion permit rotation but sharply limit flexion and extension. Incontrast, the structure of the vertebral articulating surfaces in thelumbar region inhibits rotation, but allows excellent freedom ofextension and adequate flexion. Extension of the lumbar spine wellbeyond the normal, or static, lumbar lordosis is therefore possible.However, flexion of the lumbar region will at most result in aflattening of the normal lordotic curve, since the geometry of thelumbar vertebrae does not safely permit sufficient flexion to producekyphosis.

[0007] The entire spine is balanced at its base on the sacrum, andpivotally connected to one another through the lumbosacral joint. Thesacrum and ilia move as one unit and comprise the pelvis, which in turnis connected to the legs via the hip joints.

[0008] Movement of each region of the spine is controlled by aparticular muscle or muscle group. The rectus abdominous is responsiblefor flexion of the lumbar vertebrae, and when toned properly, assists insupporting the lower back against hyper-extension. It is attached at thetop to the costal cartilage of the 5th, 6th and 7th ribs and the xiphoidprocess of the sternum, and below to the pubic bone of the pelvis.Contraction of the rectus abdominous increases the thoracic curve andflattens the lumbar curve by approximating the thorax and pelvisanteriorly. However, since flexion/extension of the thoracic spine issharply limited, most of the shortening between the thorax and pelviseffected by contraction of the rectus abdominous is attributed toflexion of the lumbar spine. It is believed that this trunk flexionoccurs primarily at the lumbosacral joint, accounting for as much as 75%of the total flexion. Additional flexion occurs between the remaininglumbar vertebrae and is limited to a reversal of the static lordosis toa flattened position. Any attempt to go beyond this point, at which thenormal lordotic curve is flattened, will place undue stress on thelumbar spine.

[0009] Well known in the prior art, the sit-up type exercise has longbeen relied upon to condition and strengthen the muscles in theabdominal area, and in particular the rectus abdominous. In suchexercises, by forcing the rectus abdominous to contract to shorten thedistance between thorax and pelvis, the weight of the upper body actingagainst gravity provides a resistance against the contraction, in turnconditioning the muscle.

[0010] Originally, the standard full sit-up was performed by raising thetrunk to a sitting position from a supine position, with legs eitherfully extended or bent at the knees. This motion, however, by applyingforces tending to urge the lumbar vertebrae into flexion beyond aflattening of the lordotic curve, was found to exert undue stress on theregion of the lower back, often resulting in trauma. Full sit-upspracticed over a prolonged period may lead to degenerative changesresulting in low back mechanical instability, chronic pain or evendisability.

[0011] To overcome this negative limitation, this type of abdominalconditioning exercise evolved into the well known “crunch” style sit-up,in which an individual in a supine position, with legs bent, raises thehead and shoulders a sufficient distance to curl the trunk and tense theabdominal muscles. Although alleviating the traumatic effects to thelower back caused by the traditional full sit-up by eliminating theoffending range of motion, the “crunch” style sit-up has been less thanperfect in providing efficient conditioning of the rectus abdominous.

[0012] Another drawback in prior art abdominal strengthening exercisesinvolving trunk raising is the failure to isolate against involvement ofother muscles, and in particular the iliopsoas. The iliopsoas is apowerful muscle component of the hip flexors, the group of musclesresponsible for rotation of the pelvis about the hip joints, whichattaches within the abdomen on the lumbar vertebrae across the pelvisonto the proximal femurs. Bending motion at the waist is accomplished bya combination of actions of the rectus abdominous and hip flexors. Whenbending at the waist with legs extended, for example in an attempt totouch one's toes in the performance of a full sit-up, trunk flexioneffected by contraction of the rectus abdominous alone would not besufficient to complete the action, since most of the bending of thespine anteriorly is confined to a straightening of the lordotic curve inthe lumbar spine. Rotation of the pelvis about the hip joints istherefore necessary to accomplish further bending, which requirescontraction of the iliopsoas.

[0013] The iliopsoas connects at its upper termination to the anteriorlumbar spine. While an individual is standing, or in a supine positionwith legs fully extended, the pull of the iliopsoas applies mildanterior tension on the lumbar spine, and maintains the static lordoticcurve of the lumbar spine.

[0014] In a desire to eliminate involvement of the iliopsoas duringtrunk raising, it has long been suggested that the situp type exercisebe performed with legs bent at the knees. By bending the knees, the hipsare also flexed, and the iliopsoas is passively shortened. It wasthought that placing the muscle in this slackened state would remove itsinvolvement while performing trunk raising. However, subsequent studieshave suggested that passively shortening the iliopsoas by flexing thehips in the bent knee position does not eliminate their involvementduring performance of the sit-up type exercise. On the contrary,researchers believe the iliopsoas, in a mechanically less effectiveposition when shortened, is loaded to a greater degree than if the trunkraising were to be performed with legs extended and the iliopsoas in amore elongated state. Exercising the iliopsoas through a short arc ofmotion, as while in the bent knee position with hips flexed, may overtime result in over-strengthening and an undesirable shortening of thehip flexors.

[0015] Bending the knees and hips while performing a sit-up typeexercise also introduces another undesirable effect. When feet are incontact with the floor, bending of the knees flexes the femurs. As aconsequence, the pelvis tilts posteriorly, and the lordotic curvature isflattened. The effectiveness of any abdominal exercise performed whilein this position, including full and “crunch” sit ups, would be severelylimited, since most of range of motion affected by contraction of therectus abdominous is confined to a straightening of the static lordoticcurve of the lumbar spine, of which as much as 75% is due to tilting ofthe pelvis with respect to the interspace between the fifth lumbarvertebra and the sacrum, which has already been accomplished withoutusing the rectus abdominous. In the bent knee position, the lowerabdominal muscles are passively shortened, placing them in a weakenedstate, and preventing maximum contraction. Moreover, exercising themover the short arc of motion remaining may lead to lower abdominalbulging or an undesirable shortening thereof.

[0016] Another exercise, the leg lift, has also been practiced in theprior art in a desire to bring about a strengthening of the rectusabdominous, particularly over the lower region thereof. The classicalform of this exercise was performed from a supine position, andconsisted of raising both legs, with knees maintaining a straight legposition.

[0017] Generally this exercise has been contraindicated, except forextremely well-conditioned individuals, and for the following reasons.During leg raising with both legs fully extended, approximately thefirst 30 degrees of motion is accomplished by the iliopsoas. Because ofthe weight of the legs and the poor mechanical advantage, contraction ofthe iliopsoas in an attempt to elevate the legs instead generally causesan undesirable hyperextension of the lordotic curve, rather thanresulting in upward movement of the legs. In addition, the individualmay frequently hold his breath during performance of the exercise, whichmay cause other undesirable effects.

[0018] Numerous abdominal exercise appliances have been provided in theprior art, in an attempt to condition and strengthen the rectusabdominous. However, in many ways these have failed to adequatelyaddress the need for a portable, lightweight appliance which when used,effectively isolates and safely exercises the rectus abdominous andother abdominal muscles.

OBJECTS AND SUMMARY OF THE INVENTION

[0019] Accordingly, it is an object of the invention to provide anexercise appliance and a method of using the same for strengthening theabdominal muscles of a user, particularly the rectus abdominous, whichovercomes the drawbacks of the prior art.

[0020] It is a further object of the invention to provide the exerciseappliance and a method of using the same which isolates the abdominalmuscles and minimizes involvement of the hip flexors.

[0021] It is a still further object of the invention to provide theexercise appliance and a method of using the same which exercises therectus abdominous over a wider range of motion, firing the muscle at ahigher intensity, for enhanced strengthening and conditioning, whilereducing lumbosacral mechanical stress.

[0022] It is a still further object of the invention to provide theexercise appliance and a method of using the same which is effective fortraining an individual to maintain correct posture by teaching themotion of the posterior pelvic tilt.

[0023] It is a yet further object of the invention to provide theexercise appliance which is suitable for use by individuals of variousdegrees of physical conditioning, and in a form which is operationallyreliable, economical, lightweight, compact and portable.

[0024] Briefly stated, there is provided an exercise appliance forstrengthening and toning the abdominal muscles of an individual whichincludes a resiliently yieldable structure presenting a contact surface,such structure providing a restoring force against a force applied tothe contact surface. The contact surface has a contour suitably sizedand shaped to be at least partially fittable in the space formed betweena support surface and a static lordotic curve of a lumbar back of anindividual positioned with a remaining portion of the back of theindividual in contact with the support surface. The yieldable structureof the appliance in accordance with embodiment of the inventionadvantageously provides elastic resiliency to conformably adapt toselectively applied force by permitting deformation of the contactsurface. As used herein, the terms “elastic resiliency” and “elasticallyresilient” refer to a structure or material which yieldably resistsdeformation, a surface of such structure or material experiencingdifferential movement of area portions relative a remainder of thesurface in response to confined force applied to such area portionsagainst the restoring force. Such term is intended to embrace, forexample, any of a foam mass, an inflated balloon or other flexibleconfining structure in which is received a compressible gas or othersubstance, a tensioned elastic band or plurality of bands extendingbetween supports, or any other suitable structure or material exhibitinglike characteristics. In accordance with embodiment of the invention,movement of at least a portion of the yieldable structural portion ofthe appliance is restricted relative the support surface.

[0025] A method for strengthening the rectus abdominous using anexercise appliance in accordance with embodiment of the presentinvention includes placing the elastically resilient, yieldable portionof the appliance in the space formed between a support surface and anormal lordotic curve of an individual positioned with a back of theindividual in contact with the support surface. The support surface maybe a floor, table top or exercise bench, in which case the individuallies in a supine position. Alternatively, the support surface may be avertical wall, and the individual in an upright posture, stands with hisback in contact with the wall. Still further, the individual may be insitting position on a chair or other structure providing back support,placement of the appliance serving to restore static lordotic curvatureto the lumbar region otherwise straightened by the relaxation of thepull of the iliopsoas on the anterior lumbar spine brought about byflexion of the hips while in the sitting position. Following placementof the appliance, the individual attempts to straighten the lumbarcurvature by a contraction of the rectus abdominous and other abdominalmuscles, including the internal and external obliques and transverseabdominous, which action causes the lumbar spine to flatten against thecounter-force provided by the appliance. Because of the anatomy of therectus abdominous, two types of contractions may be performed toaccomplish a flattening of the lordotic curve. The rectus abdominous isthought to act as a two joint muscle, i.e. providing contraction overtwo regions thereof, to effect different motion. The two regions includethe lower rectus abdominous below the navel to where it connects to thepubic bone of the pelvis, and the upper rectus abdominous from above thenavel to its connection to the lower end of the rib cage. Contractingboth the lower and upper regions together results in a contractionreferred to as simultaneous or countercurrent. A more effective practiceis to perform the contractions of each region in sequence, known as aconcurrent contraction, which fires the muscle more powerfully for moreefficient conditioning. Therefore, advantageously, conditioning of therectus abdominous may be divided into two exercises, each performedseparate from the other, directed to one of the upper and lowerabdominal regions. To concentrate on conditioning the lower abdominal,the individual will posteriorly tilt the pelvis by actively contractingthe rectus abdominous primarily over its lower region. If instead theindividual wishes to concentrate on the upper abdominal region, the headand shoulder blades are raised by a contraction the rectus abdominous anamount sufficient to cause a flattening of the lordotic curve, and acompression of the compressible mass of the exercise appliance, whichprovides resistance against the contraction. With both exercises, thedegree of conditioning is most effective with hips extended rather thanflexed. In carrying out the method, a regimen of repeated contractionsover an uninterrupted exercise time period of the abdominal muscles toeffect straightening of the lumbar back against the elastic resiliencypresented by the contact surface is deemed advantageous in achievingincreased muscle fitness.

[0026] A structural embodiment particularly adapted to portable useprovides the yieldable structure in the form of a compressible massfabricated from a elastically resilient material, such as elastomericfoam, thereby providing inherent resistance against deformation of itsoriginal shape. One side of the compressible mass will advantageously beof a generally flattened shape to permit secure contact with the supportsurface. When placed in direct contact with the support surface,movement of the compressible mass comprising the yieldable structure isrestricted, and substantially all applied forces are translated intocompression of the mass. The other side is of a suitable curved shape toconform with the static lordotic curvature of the individual. Placementof the appliance in the space between the normal lordotic curve and thesupport surface provides a direct counter-force against an attempt bythe individual to straighten the lordotic curve brought about by activecontraction of the abdominal muscles, particularly the rectusabdominous. Performing repeated compression of the mass by astraightening of the lordotic curvature effectively conditions andstrengthens the abdominal muscles by forcing them to contract against aresistance. In an advantageous embodiment, a kit provides the user witha plurality of such compressible masses, each having a different degreeof compressive resiliency, from which the user selects a suitable onedepending on the progressive level of physical conditioning applicableto the particular user. The appliance may also be provided with a sensorwhich can output an audible or other type feedback signal indicative ofthe degree of compression of the mass, to insure proper performance ofthe exercise by the individual.

[0027] In accordance with an alternative embodiment, the applianceincludes a pair of spaced apart lateral supports between which one ormore elastic members, conveniently in the form of elastic bands, extend.The bands are advantageously tensioned to provide a desired degree ofelastic resiliency when acted upon by a lumbar back of an individualbrought in contact therewith in a manner analogous with the previouslydescribed embodiment. Means are optionally provided to permituser-selectable tensioning of the bands.

[0028] The above, and other objects, features and advantages of thepresent invention will become apparent from the following descriptionread in conjunction with the accompanying drawings, in which likereference numerals designate the same elements.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029]FIG. 1 is perspective view of an embodiment of the exerciseappliance in accordance with the present invention;

[0030]FIG. 2 is perspective view of another embodiment of the exerciseappliance in accordance with the present invention;

[0031]FIG. 3 is a schematic view of an individual prior to performing amethod of strengthening the rectus abdominous using the exerciseappliance of the present invention;

[0032]FIG. 4a is a schematic view of an individual performing a methodof strengthening the rectus abdominous using the exercise appliance ofthe present invention, with concentration on the lower abdominal region;

[0033]FIG. 4b is a schematic view of an individual performing a methodof strengthening the rectus abdominous using the exercise appliance ofthe present invention, with concentration on the upper abdominal region;

[0034]FIG. 5 is a schematic view of an individual prior to performing amethod of strengthening the rectus abdominous using the exerciseappliance of the present invention in a seated position;

[0035]FIG. 6a is a schematic view of an individual performing a methodof strengthening the rectus abdominous using the exercise appliance ofthe present invention while seated, with concentration on the lowerabdominal region;

[0036]FIG. 6b is a schematic view of an individual performing a methodof strengthening the rectus abdominous using the exercise appliance ofthe present invention while seated, with concentration on the upperabdominal region;

[0037]FIG. 7 is cross-sectional view taken of another embodiment of theexercise appliance in accordance with the present invention, includingreplaceable inserts to vary a degree of resiliency;

[0038]FIG. 8 is a cross-sectional view of an abdominal exercise kit;

[0039]FIG. 9 is a bottom elevation of a further embodiment the exerciseappliance in accordance with the present invention, including means forproviding structural rigidity;

[0040]FIG. 10 is a perspective view of another embodiment of theexercise appliance in accordance with the present invention;

[0041]FIG. 11 is a perspective view of an alternate embodiment of theexercise appliance shown in FIG. 10, showing the exercise appliancemounted to an exercise bench;

[0042]FIG. 12 is the embodiment of FIG. 10 with the addition of a heightadjustment mechanism, shown in detail;

[0043]FIG. 13 is a cross-sectional view of a further embodiment of theexercise appliance in accordance with the present invention, includingmeans for emitting an audible feedback signal in response tocompression; and

[0044]FIG. 14 is a perspective view of a kit providing a plurality ofexercise appliances in accordance with embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0045] Referring now to the figures, and in particular FIG. 1, there isshown, generally at 10, an abdominal exercise appliance, in accordancewith the invention. Abdominal exercise appliance 10 of the preferredembodiment is made of a compressible, elastically resilient foam andformed in a shape suitable for placement between the lumbar spine of anindividual and a support surface against which a remaining portion of aback of the individual is in contact. In the embodiment shown in FIG.1., the shape is that of a longitudinally bisected football, having acurved upper surface 1 and opposed end poles 2 a and 2 b at thetermination points of a longitudinal axis 3. In this embodiment,abdominal exercise appliance 10 is designed to be positioned during usewith longitudinal axis 3 oriented in a direction across the individual'sback. The compressible foam from which abdominal exercise appliance 10is formed is a resilient material which resists compression and whichreturns essentially to its original shape upon a release of an appliedforce. For example, urethane foams and the like having elastomericproperties perform satisfactorily in such application.

[0046]FIG. 2 is another embodiment of the abdominal exercise appliance,in accordance with the invention, shown generally at 10′. Abdominalexercise appliance 10′ is also fabricated or molded from a compressiblefoam material demonstrating elastic resiliency, and but is insteadgenerally saddle shaped, having a longitudinal axis 3′ which is orientedin a direction across the individuals back during use. A curved uppersurface 1′ is centrally located along longitudinal axis 3′. A pair oflateral supports 4 a and 4 b are disposed on lateral ends of abdominalexercise appliance 10′ and contact the left and right sides of theindividual, to provide stability during performance of the describedmethod of strengthening the rectus abdominous which is discussed indetail below. For purposes of disclosure, it is noted that only twoshapes have been shown. However many others may be developed withoutdeparting from the scope of the invention.

[0047] Referring now to FIGS. 3, 4a and 4 b, a method of using theabdominal exercise appliance of the present invention will be described.An individual 20 lies, for example as shown, in a supine position on asupport surface 11. Support surface 11 may be a floor, a table, exercisebench or any suitable, relatively flat surface. Although a horizontalsurface has been selected for purposes of disclosure, the describedmethod may also be performed in an upright position, with the back ofindividual 20 in contact with a vertical wall. Tilted support surfacesare also feasible. Additionally, the individual may be in an uprightsitting position in a chair in supported contact with a back thereof,the back of the chair being the support surface. Moreover, becauseeffective use of abdominal exercise appliance 10 is gravity independent,it may find application in the weightlessness of outer space, requiring,however, that the individual be secured by straps or the like to thesupport surface during performance of the disclosed method.

[0048] Abdominal exercise appliance 10 is fittable between a lumbarspine 12 having a normal or static lordotic curve and support surface11, as shown in FIG. 3. Where used herein, a normal or static lordoticcurvature refers to a degree of curvature generally present in a lumbarspine when an individual with normally healthy posture is in an uprightposition. It is noted that with legs 13 fully extended, as shown in FIG.3, the static lordotic curve is maintained by the pull of the iliopsoason the anterior lumbar spine, creating a space in which abdominalexercise appliance 10 is fittable. However, it is alternatively quiteacceptable to bend the knees, relaxing the pull of the iliopsoas,passively straightening lumbar spine 12. In fact, this action isunavoidable, when the exercise is to be performed in a sitting positionin a chair, as described below with reference to FIGS. 5, 6a and 6 b.Despite the straightening of lumbar spine 12, abdominal exerciseappliance 10 is still fittable between lumbar spine 12 and supportsurface 11, since static lordotic curvature is restorable by effort onthe part of the individual to anteriorly tilt the pelvis, designated bythe numeral 15 in FIG. 4a, i.e. in a direction opposite that indicatedby the curved arrow shown. This notwithstanding, the resiliency ofabdominal exercise appliance 10 once placed between lumbar spine 12 andsupport surface 11 is generally sufficient to restore and maintainstatic lordotic curvature of lumbar spine 12 otherwise straightened bythe relaxation of the pull of the iliopsoas on the anterior lumbar spine12 brought about by flexing the hips, for example while sitting or lyingwith knees bent. Bending the knees may actually be advisable for certainindividuals having an overly developed lordotic curvature, for examplewhere tight hip flexors exert undue anterior pull on lumbar spine 12.These individuals would be advised to bend their knees at least anamount sufficient to release the excessive strain of the iliopsoas,reducing the lordotic curvature to a normal degree.

[0049] A rectus abdominous 14 includes a lower abdominal region 14 a andan upper abdominal region 14 b. Rectus abdominous 14 connects at itslower termination to the pubic bone of pelvis 15, and at its uppertermination to a lower part of a rib cage 16 (the costal cartilage ofthe 5th, 6th and 7th ribs and the xiphoid process of the sternum). In anadvantageous embodiment of the present invention, abdominal exerciseappliance 10 has a height, as measured from support surface 11, thatslightly exceeds the distance between the apex of the normal lordoticcurve of lumbar spine 12 and support surface 11. In this way, a gentleupward pressure is exerted against lumbar spine 12 by abdominal exerciseappliance 10 prior to performing any action, however not enough to causeexcessive hyperextension. Rectus abdominous 14 is placed in a conditionof prestretch as a result of the pre-applied upward force on lumbarspine 12. Studies have shown that moderate prestretching of a muscleimmediately preceding a contraction thereof, enables it to contract moreforcefully than if prestretching is not performed, increasing the rateof beneficial conditioning of the muscle during exercise, as well aspreventing a shortening of the muscle.

[0050] It is noted that the rectus abdominous is thought to act muchlike a two-joint muscle. Capable of controlling two distinct bodymotions by separate contractions, two-joint muscles are not optimallyeffective if shortened over both joints simultaneously. Therefore,advantageously, an exercise directed to conditioning such muscles shouldideally include contraction of each of the two regions, separate of theother. Similarly, to obtain the most forceful contraction, and hence themost concentrative conditioning in each of the two regions ofcontraction of the rectus abdominous, i.e. the lower part thereof, whereit connects to the pelvis, and the upper part, where it connects to therib cage, each region should be made to contract separately from theother. It must be noted, however, that the region not activelycontracted still fires and is not completely silent.

[0051] Referring now to FIGS. 4a and 4 b, two actions are illustrated,one directed to the conditioning of lower abdominal region 14 a, and theother to the conditioning of upper abdominal region 14 b, respectively.Referring first to FIG. 4a, a compression of abdominal exerciseappliance 10 is accomplished by initiating contraction of lowerabdominal region 14 a. Individual 20 concentrates on tilting pelvis 15posteriorly, i.e. in the direction as indicated by the curved arrow, byactive contraction of rectus abdominous 14, and in particular lowerabdominal region 14 a. At the same time, head 17 and shoulder blades 18are maintained in contact with support surface 11, which if lifted,would cause simultaneous contraction of upper abdominal region 14 b,thereby weakening the contraction of lower abdominal region 14 a. Thenormal lordotic curve of lumbar spine 12 is flattened by the contractionof lower abdominal region 14 a to effect the tilting of pelvis 15posteriorly, as illustrated in the figure (the flattened position oflumbar spine designated 12′ in FIGS. 4a and 4 b). The resisting forceagainst compression of abdominal exercise appliance 10 provides loadingon the contracting lower abdominal region 14 a. Once compression ofabdominal exercise appliance 10 is complete, individual 20 allows pelvis15 to tilt anteriorly, returning it to its original position in FIG. 3,and relaxing lower abdominal region 14 a. In this position, abdominalexercise appliance 10 returns to its original shape, and in accordancewith the aforementioned advantageous embodiment, places rectusabdominous in prestretch, providing maximum conditioning from subsequentcompression. The above described actions are performed for a desirednumber of repetitions to effectively condition lower abdominal region 14a of rectus abdominous 14.

[0052] Turning now to FIG. 4b, a compression of abdominal exerciseappliance 10 is accomplished by initiating contraction of upperabdominal region 14 b. Individual 20 now concentrates on moving head 17and shoulder blades 18 away from support surface 11, as indicated by thedirection of the curved arrow, to curl the trunk, by active contractionof rectus abdominous 14, and in particular upper abdominal region 14 b.The normal lordotic curve of lumbar spine 12, as shown in FIG. 3, ismoved to flattened lumbar position 12′ by the contraction of upperabdominal region 14 b to effect a curving of the trunk by pulling on therib cage 16 where rectus abdominous 14 connects thereto, as illustrated.Ideally, care is taken not to allow pelvis 15 to tilt posteriorly byaction of lower abdominal region 14 a to assist in the flattening oflumbar spine 12′. If such were permitted to occur, the simultaneouscontraction of lower abdominal region 14 b would hinder as forcible acontraction of upper abdominal region 14 b. Head 17 and shoulder blades18 are lifted only an amount sufficient to flatten the normal lordoticcurve of lumbar spine 12, as shown in FIG. 3, to flattened lumbarposition 12′, and to compress abdominal exercise appliance 10. At thispoint shoulder blades 18 should generally just clear support surface 11.There is no beneficial reason for going beyond this point since lumbarspine 12 does not safely permit sufficient flexion to produce kyphosis.The resisting force against compression of abdominal exercise appliance10 provides loading on the contracting upper abdominal region 14 b. Oncecompression of abdominal exercise appliance 10 is complete, individual20 lowers head 17 and shoulder blades 18 back to contact with supportsurface 11, returning to the original position in FIG. 3, and relaxingupper abdominal region 14 a. In this position, abdominal exerciseappliance 10 returns substantially to its original shape, as with thepreviously described method embodiment. The above described actions areperformed for a desired number of repetitions to effectively conditionupper abdominal region 14 a of rectus abdominous 14.

[0053] Referring now to FIGS. 5, 6a, and 6 b, use of the abdominaldevice when a user is in a seated position is described. Individual 20sits on a suitable chair 19 advantageously having a secure chair back11′ which serves as a support surface. As mentioned herein, bending ofknees 13 a of legs 13 of individual 20 when normally seated inupright-back chair passively straightens lumbar spine 12 by relaxing thepull of the iliopsoas on pelvis 15. Therefore, as noted, and as depictedin FIG. 5, prior to performing a repetition in accordance with anembodiment of the invention, before individual 20 restores the lordoticcurvature of lumbar spine 12 by anteriorly tilting the pelvis, i.e. inthe direction indicated by the curved arrow, creating a space in whichexercise appliance 10 is fittable. Generally, once placed, the restoringforce provided by exercise appliance 10 is sufficient to assist inrestoring the curvature to lumbar spine 12 for subsequent repetitions.From this position, two exercises targeted respectively to the lower andupper abdominal regions 14 a and 14 b, shown in FIGS. 6a and 6 b. Theexercises are performed in an analogous manner to those described withreference to FIGS. 3, 4a and 4 b performed in a supine position. Forexercise targeted to the lower abdominal region, as shown in FIG. 6a,individual concentrates on tilting pelvis 15 posteriorly in thedirection of the curved arrow. Alternatively, as shown in FIG. 6b,individual 20 concentrates instead on moving head 17 and shoulder blades18 away from support surface (chair back) 11′. In both cases, oncecompression of abdominal exercise appliance 10 is complete, individual20 returns to the starting position depicted in FIG. 5, and thedescribed actions are performed for a desired number of repetitions toeffectively condition rectus abdominous 14.

[0054] Although the above methods are described with reference to theirbenefits associated with the rectus abdominous, other abdominal muscleswill benefit from performance of the described exercises. Among these,for example, are the internal and external obliques which also play arole in flexing the vertebral column to approximate the thorax and thepelvis when acting bilaterally, will be strengthened when forced tocontact against the resisting force of the exercise appliance of thepresent invention. It is further noted, that although the advantageousembodiments described above are directed to performance of exerciseswhich stress a concurrent contraction of each of the upper and lowerregions of the rectus abdominous, benefit to the abdominal muscles willstill be derived from performance of a simultaneous contraction, and iscontemplated to be within the scope of the invention as claimed herein.

[0055]FIG. 7 is a cross-sectional illustration of another embodiment ofthe abdominal exercise appliance, in accordance with the invention,adapted for portable use, which allows selective alteration of degreesof resistance, and is shown generally at 30. Abdominal exerciseappliance 30 includes a body 31 and a series of removable inserts 32.Only one of inserts 32 is shown since the dimensions for each areuniform. Body 31 is molded or fabricated from a compressible foammaterial, and has an external shape and physical characteristics inconformance to those discussed with regard to the embodiments of FIGS. 1and 2. A cavity 33 is formed for captively receiving a selected one ofinserts 32, for example, having an opening thereof in the lower surfaceof body 31. In an advantageous embodiment, inserts 32 have externaldimensions slightly larger than the internal dimensions of cavity 33,requiring inserts 32 to be press fit into cavity 33, thereby holdingbody 31 in joined relationship to the selected one of inserts 32.Inserts 32 are made of a foam material, each member of the set having adifferent density from remaining ones of the set, to present a differentmodulus of elasticity, i.e. degree of compressive resiliency, ofabdominal exercise appliance 30 based on which insert 32 is installed inbody 31. It is noted that by disposing the opening of cavity 33 suchthat inserts 32 are inserted from the flat side of body 31, i.e. theside designed to contact the support surface, the effect of the densityof the insert selected on the compressibility of the overall abdominalexercise appliance 30 by orientation in direct relation to thecompression forces generated by a straightening of the lumbar lordosisis maximized. Physical alignment with the direction of the appliedcompressive force also provides better mechanical stability of abdominalexercise appliance 30 during use.

[0056] It will be understood by those skilled in the art that althoughonly foam inserts have been shown for purposes of disclosure many othersuitable possibilities exist for accomplishing the same result. Forexample, instead of varying foam density, springs having variouscompression characteristics may be imbedded within a uniform densityfoam insert, each insert for insertion into the body. Or, by way offurther example, air or hydraulic pressure may be varied within abladder located within the body to accomplish variance of degree ofcompressibility of the abdominal exercise appliance.

[0057] The present invention will find application among a largecross-section of the population. Lordotic curve varies with theindividual, and consequently so too the space between the lumbar spineand the support surface, within the meaning of the term static lordoticcurve as used herein. In addition, each individual will differ as totheir level of conditioning and strength. Therefore, the presentinvention may be conveniently produced and supplied in kit form,providing the individual with practical means for selectively alteringthe various parameters of the abdominal exercise appliance, includingheight and resiliency. Referring to FIG. 8, a customizing exercise kitis shown generally at 40. Included in customizing exercise kit 40 isabdominal exercise appliance 30′ and inserts 32 a, 32 b, and 32 c. As inthe previously described embodiment, exercise appliance 30′ is comprisedof a body 31′ and a cavity 33′ formed therein for receiving a selectedone of inserts 32 a, 32 b, and 32 c. In the figure, insert 32 a is showninserted within cavity 33′ in body 31′. The minimum height h ofabdominal exercise appliance 30′ is selected based upon a statisticalminimum lordotic curve of the population, since its height may only beincreased over minimum height h. Body 31′ and inserts 32 a, 32 b, and 32c are of the same shape and material as those described prior withregard to the embodiment shown in FIG. 7.

[0058] Customizing exercise kit 40 further includes at least one heightadjustment spacer 34 (two are shown). Height adjustment spacers 34 areflat, conveniently having a perimeter matching in shape that of body31′, and are made of a compressible foam material having similarcharacteristics to those from which body 31′ and inserts 32 a, 32 b and32 c are produced. One consideration, however, is that the foam used tomake height adjustment spacers 34 should not be so resilient as toresist compression entirely, and prevent complete flattening during use,nor should they be too soft so as to prematurely collapse when used inconjunction with a more resilient one of inserts 32 a, 32 b and 32 c.Disposed on the lower surface of body 31′ are means for mechanicallyinterconnecting body 31′ with a height adjustment spacer 34 placedadjacent thereto. In an advantageous embodiment, an attachment layer 35is made of one of the component elements of a gripping fabric such asfor example the type manufactured under the trade name VELCRO, and isfixed to the lower surface of body 31′ with the gripping surface facingoutwardly. Height adjustment spacers 34 also have spacer attachmentlayers 36 a and 36 b, attachment layer 36 a being made of the componentelement adapted to cooperate with the element of attachment layer 35,and attachment layer 36 b made of the same component element asattachment layer 35. As a result, any number of height adjustmentspacers 34 may be removably added to body 31′ to increase the height ofabdominal exercise appliance 30′ in excess of minimum height h asrequired to obtain proper fit to the individual.

[0059] Referring now to FIG. 9, another embodiment of the abdominalexercise appliance, in accordance with the invention is shown, generallyat 50. This further embodiment includes a feature particularly usefulwhen performing the exercise on a padded surface, for example anexercise mat, as is often desirable insofar as there is reduced dangerof trauma to various portions of the body in contact with the supportsurface. A body 41, fabricated from a compressible foam material, andhaving an external shape and physical characteristics in conformance tothose discussed with regard to the embodiments of FIGS. 1 and 2,includes a cavity 43 formed therein, having an opening in a lowersurface of body 41, i.e. the flattened surface facing the supportsurface during use, for captively receiving an insert 42, selected froma set of inserts (not shown) having varying density, as has already beenaddressed herein. When performed on a mat, the exercise method performedin accordance with the invention may result in an uneven distribution offorces causing an undesirable deformation of the mat itself below theexercise appliance, particularly when the mat is softer than theparticular degree of resilient counterforce selected for the exerciseappliance. Consequently maximum conditioning is prevented. Addressingthis consideration, an embodiment of abdominal exercise appliance 50includes means for providing rigidity in a plane parallel to andproximate with the support surface, provided, for example, in the formof a plate member 44. Plate member 44 is constructed of any suitablematerial which can provide rigidity to abdominal exercise appliance 50and thereby allow even distribution of pressure in the direction of thesupport surface applied by a straightening of the static lumbar lordoticcurvature during performance of the exercise. Plate member 44 isfastened to the lower side of body 41 by suitable means. In theembodiment as described, for example, plate member 44 is swivelablyattached at one end thereof to a corresponding end of body 41. A rivet47 affixed to body 41 pivotably holds plate member 44 to body 41, a headof which is retained within a countersunk portion 48 recessed below asurface of plate member 44, preventing the head of rivet 47 fromprotruding beyond the surface of plate member 44, which would otherwiseadversely affect stability of abdominal exercise appliance 50, whenplaced on a rigid support surface, for example when not being used on acompressible mat. Shown in its opened position in FIG. 9 which allowsreplacement of insert 42, plate member 44 may be subsequently closed bypivoting thereof in a direction of the curved arrow. A rivet 45, affixedto body 41 at an end thereof opposed to rivet 47, is received within areceiving groove 46. Continued rotation of plate member 44 causes a headof rivet 45 to snap into a countersunk receiving portion 49 recessedbelow a surface of plate member 44. The head of rivet 45 is separatedfrom the lower surface of body 41 a distance approximately equal to thethickness of plate member 44 within the region of countersunk receivingportion 49. Consequently, plate member 44 is maintained in closedposition unless pivoted in a direction opposite the arrow, whilesimultaneously exerting pressure in the region of the countersunkreceiving portion in a direction against body 41. It is noted that platemember 44 may have a shape substantially matching a perimeter of body41, may be slightly smaller, or may be larger, extending evensubstantially beyond the perimeter of body 41. It is further noted, thatplate member 44, in addition to providing rigidity, further providesmeans for retaining insert 42 captively within cavity 43 of body 41independent from those already described in the prior embodiments,obviating the need for press-fit engagement.

[0060] With regard to the appliance in accordance with the invention, itis noted herein that any elastically resilient structure for providing adirect counterforce to a straightening of the static lordotic lumbarcurve, the force being directed from behind the individual, iscontemplated within the intended scope of the appended claims. Forexample, although the appliance of the above embodiment convenientlyprovides the counterforce in the form of a compressible foam mass, anexercise appliance in accordance with the invention may alternately takethe form of an inflatable pillow of suitable shape to be fittablebetween a support surface and the static lordotic curve of theindividual. Compressibility of the trapped air would provide a restoringforce to counter a deformation of the pillow. In a further embodiment,as detailed below with reference to the figures, the exercise applianceneed not in fact be a confined mass, including rather a structurepresenting a curved elastic surface providing resistance to deformationthereof, as described below.

[0061] Referring now to FIGS. 10 and 11, there is shown, generally at100, an alternate embodiment of an abdominal exercise appliance, inaccordance with the invention. Abdominal exercise appliance 100 includesa frame 101 fabricated from a suitable rigid material. Frame 101 iscomprised of a pair of interconnected frame sections 101 a and 101 b.Frame 101 includes a pair of arcuate portions 102 a and 102 b carried onframe sections 101 a and 101 b respectively. Arcuate portions 102 a and102 b are disposed laterally, arranged crosswise a longitudinal axis 103of abdominal exercise appliance 100. A series of elastic band members104 are attached at their opposed ends to each arcuate portion 102 a and102 b, and are tensioned therebetween, collectively defining aresiliently deformable surface configuration of a shape corresponding toa locus of their connection points 105, shown conveniently as rivets inthe figures, on arcuate portions 102 a and 102 b. For example, since thelocus of points in the present case is semi-circular, the surfacedefined by elastic band members 104 is that of a longitudinally bisectedcylinder. Means for tensioning the series of elastic band members 104 isprovided to permit selection of the degree of resistance againstdeformation of the surface configuration, to provide ideal conditioningto individuals of varying degrees of fitness. In the embodiment asshown, for example, frame sections 101 a and 101 b are provided withcorrespondingly sized slide portions 106 a and 106 b extending from theends of arcuate portions 102 a and 102 b, to allow reception of onewithin the other. Slide portions 106 a and 106 b function as a base forframe 101, enabling secure contact with a support surface. Slide portion106 a is tube shaped, having a generally rectangular cross section, andis sized to receive a smaller, correspondingly shaped slide portion 106b for slidable engagement therein. A series of alignment holes 107 areprovided through each of slide portions 106 a and 106 b, which whenaligned, allow frame 101 to be locked in position by inserting a lockingpin 108, thereby maintaining a desired tension setting. Arcuate portions102 a and 102 b are sufficiently laterally spaced from one another topermit an individual, during performance of the above describedabdominal exercise, to lie between arcuate portions 102 a and 102 b,with elastic band members 104 oriented crosswise to the back of theindividual, conforming to the static lumbar curvature. Preferably, slideportions 106 a and 106 b are of flattened configuration to present areduced vertical profile, such that they are not raised significantlyabove the support surface where they would interfere with the back ofthe individual when the static curvature is straightened. In thisregard, however, if the individual is uncomfortable, a pair of mats maybe butted against slide portions 106 a and 106 b from either side,essentially raising the support surface to be even with, or above, thetop surfaces of slide portions 106 a and 106 b. This is not an issuewhen abdominal exercise appliance 100 is used in combination with anexercise bench, a use for which the present embodiment is particularlysuited, and which is described below.

[0062] Referring to FIG. 11, abdominal exercise appliance 100 isattached to an exercise bench 110 by any suitable conventional clampingmeans (not shown) or is permanently welded thereto at a point thereonwhich will not interfere with the slidable tension adjustment meansdescribed with regard to the preceding embodiment. Whatever mountingmeans are employed, it is preferable to allow selective placement ofabdominal exercise appliance 100 at a position along the length ofexercise bench 110, to compensate for anatomical differences amongindividuals. Further, the mounting means would, in the preferred case,allow raising and lowering of abdominal exercise appliance 100 withrespect to exercise bench 110 to permit the height of the curved elasticsurface above the surface of exercise bench 110 to be selectivelyaltered dependent upon the degree of static lordotic curvature of theparticular individual. Exercise bench 110 is raised above the floor by apair of support members 111, the top surface of exercise bench 110providing the support surface for the individual lying in a supineposition. In this application, slide portions 106 a and 106 b areoriented below the exercise bench (shown by broken lines in FIG. 11) andtherefore cannot in any way interfere with the back of the individual,particularly when elastic band members 104 are compressed.

[0063] It is further noted that means for adjusting the height of thecurved elastic surface configuration above the support surface may beprovided when the above embodiment is used separate from a bench. FIG.12 illustrates an abdominal exercise appliance 100′, detailing a slidemechanism, similar in structure to slide portions 106 a and 106 b, forconnecting arcuate portions 102 a and 102 b to frame 101. (Note that thedetail shows only arcuate portion 102 b, but the corresponding structureof arcuate portion 102 a is analogously configured). A tubular frameslide portion 115 a of rectangular cross section, is sized to receivetherein, in sliding engagement, a correspondingly shaped, smallerarcuate slide member 115 b. A series of alignment holes 107′ areprovided through each of slide portions 115 a and 115 b, which whenaligned, allow frame 101 to be locked in position by inserting a lockingpin 108′, thereby maintaining a desired height setting of abdominalexercise appliance 100′.

[0064] It is still further noted, that an abdominal exercise appliancein accordance with the invention may be constructed which includes anelastic layer tensioned between lateral support portions of a frame asdetailed above, which instead of including elastic band members, employsan elastic fabric sheet, attached on opposed sides to correspondinglateral support portions, forming a curved elastic surface.Additionally, the support frame need not include arcuate shapedportions. It is only necessary that the locus of connecting points tolateral portions of the support frame create a deformable elasticsurface of suitable shape for contact with the lumbar back region, andthat the lateral support portions be separated sufficiently so as not tointerfere with body motion during exercise. It will also be recognizedthat many suitable means for varying the tensioning of the stretchedelastic layer alternative to those described above may be employed,without departure from the invention.

[0065] In addition to its use in conditioning the abdominal muscles, thepresent invention will also find utility in teaching the posteriorpelvic tilt. The posterior pelvic tilt is a practice useful in improvingposture and maintaining integrity of the lower back by reducing thelordotic curvature of the lumbar spine, however the mechanics of itsperformance are often difficult for a patient to learn. In yet anotherembodiment in accordance with the invention, directed in part to thisteaching application, an abdominal exercise appliance is shown in FIG.13 which includes means for audible feedback during performance of theabove described abdominal exercise, generally designated 130. Thestructure of abdominal exercise appliance 130 is equivalent to thatalready described with reference to FIG. 7, and includes a body 131 anda cavity 133 formed therein for receiving a selected one of a set ofinserts of varying compressibility, for example including an insert 132,shown inserted within cavity 133. Means for providing feedbackresponsive to a compression of abdominal exercise appliance 130 areprovided, conveniently for example in the form of a bellows 134 receivedwithin a receiving hole 135, a compression of bellows 134 expelling airthrough an outlet passage 137 communicating with an exterior ofabdominal exercise appliance within which a reed 136 is disposed.Compression of abdominal exercise appliance 130 thereby produces anaudible feedback signal in response thereto, indicating properperformance of the abdominal exercise or posterior pelvic tilting.

[0066] It is noted that any number of other possible arrangements arecontemplated which can alternately provide the desired feedback. Forexample, electronic means sensing and emitting means may be provided aspart of any of the embodiments within the scope of the invention toeffect emission of a feedback signal in response to application of acompression force brought about by a straightening of the static lumbarlordosis. The feedback signal produced thereby may be audible or anyother suitable detectable type. Further, the above selected means mayadditionally include a means for varying the level of feedback relativeto the degree of compression, to further indicate effectiveness of theperformance of the exercise by the individual.

[0067] Turning now to FIG. 14, a kit is depicted, generally designated140. Kit 140 includes a plurality of appliances in accordance with theinvention, each providing a dedicated degree of compressive resiliency.For purposes of depiction, appliances of the type depicted in FIG. 1 areconveniently shown as kit members 141, 141′ and 141″, each beingcomprised of material progressively more resistive to compression. Thiscan be conveniently accomplished for example by altering the degree offoaming of the material such that the amount of trapped air, and hencethe density, is regulated. Such kit could alternatively include any ofthe embodiments contemplated herein without departure from the intendedscope of the invention. Such kit, as with the appliances previouslydescribed with reference to FIGS. 7, 8 and 9, provides means forprogressively increasing a level of exercise as muscular development isaccomplished by repeated use of a preceding appliance.

[0068] Having described preferred embodiments of the invention withreference to the accompanying drawings, it is to be understood that theinvention is not limited to those precise embodiments, and that variouschanges and modifications may be effected therein by one skilled in theart without departing from the scope or spirit of the invention asdefined in the appended claims.

What is claimed is:
 1. An exercise appliance for strengthening andtoning the abdominal muscles, comprising: a pair of lateral supportssufficiently spaced apart to permit reception of the individualtherebetween; and an elastic layer tensioned between said lateralsupport structure.
 2. The exercise appliance according to claim 1,further comprising in combination: an exercise bench to which saidexercise appliance is mounted.
 3. The exercise appliance according toclaim 1, further comprising means for selectively varying a degree oftension of said elastic layer.
 4. A method of strengthening and toningthe abdominal muscles of an individual, comprising the steps of:providing an elastically resilient structure presenting a yieldablecontact surface adapted to fit between a static lumbar lordosis of aback of the individual and a support surface when a remaining portion ofthe individual's back is positioned against the support surface;positioning said structure between the support surface and the staticlumbar lordosis such that the individual's lumbar back is contactablewith at least a portion of said contact surface; supporting at least aportion of said structure in fixed relation with the support surfacesuch that motion of said structure in response to applied force issubstantially limited to that attributable to deformation thereof;straightening the static lumbar lordosis against said resistivecounterforce; returning the static lumbar lordosis at least partially tosaid static lumbar lordosis; and repeating said steps of straighteningand returning a sufficient number of times to progressively strengthenand condition the abdominal muscles.
 5. The method according to claim 4,wherein said step of straightening is accomplished by a contraction ofone of a lower and upper region of a rectus abdominous, substantiallyindependent of a remaining one.
 6. The method according to claim 4,wherein said yieldable contact surface is a portion of an exterior of aresiliently compressible envelope of shape.
 7. The method according toclaim 6, compressible envelope of shape is a mass comprised of aresiliently deformable material.
 8. The exercise appliance according toclaim 7, wherein said resiliently deformable material includes elasticfoam.
 9. The exercise appliance according to claim 5, wherein saidenvelope of shape is an inflated balloon.
 10. An abdominal exercise kitfor use in strengthening abdominal muscles of a user, said kitcomprising: a plurality of resiliently compressible bodies at leastpartially fittable between a support surface and a static lumbarlordosis of the user, members of at least a portion of said plurality ofbodies each including a different modulus of elasticity.